1. Create new document.
2. In The dialog select the "Facing Pages" checkbox and set your A5 page size and margins and page count. This will allow you to design in "reader's spreads" the way the user will see your booklet.
3. If you are going to print this yourself use File > Print Booklet... to impose and print onto your A4 sheets, otherwise, export an appropriate PDF and deliver to the printer.

Your page size should be the same as a single page in the booklet, i.e. on half or the size of the folded sheet, and the page count should be the total number of pages, in this case 8.

You'll set them up as portrait orientation, facing pages, and print on a landscape orientation sheet twice the size, with a total of 4 pages per sheet -- two on each side. Print Booklet does the arranging of the pages on the larger sheet for you.

If I have the relationship right (I'm in the US), that means you make an 8 page A5 book and print onto two A4 sheets.

Don't attempt to do an 8-page booklet in printer's spreads. It's too confusing to set up and prone to error.

For online publication you generally don't try to figure out how the user will print the booklet, if at all. Simply export a regular consecutive pages PDF. If they want to print it, they'll probably just print 8 pages and forget about folding and stapling.

If you insist on giving them a printer's spreads version (and by the way, the "spreads" checkbox in the print and export dialogs is NOT a way to make printer's spreads -- it's a way to put your reader's spreads on a single sheet for proofing or viewing as it would appear after binding), use Print Booklet as before, but instead of choosing your printer, print to PDF.

You can then post the PDF and users can print the spreads and fold, but they'll have a heck of a time working with your information unless they do that since page 8 will be next to page 1, page 2 will be next to page 7 and page 6 will be next to page 3 on the same sheet of paper.

I am considering switching from CorelDraw to InDesign and am on the 30 day trial. So limited time to learn for myself. If I switch, then I'll learn properly!

I produce for the church the monthly parish magazine - an A4 booklet. I produce the copy and send it to the printer as a Corel document. I also put it on the web site I manage as a PDF - see http://www.stbees.org.uk/magazine/2013/pm_feb.pdf for an example. I create the PDF by simply using "Print to PDF".

I think that by following the above I can set up the same document using Peter's instructions. One thing I am not certain of is who allocates the page numbers 1 & 8 and 2 & 7 etc. Me (as I do in Corel) or InDesign?

Sorry to ask what I should work out for myself but I want to make sure quickly I can do the main thing I need with InDesign and then use the 28 days I have left to assess other things.

Do you print in house, or send it out to a commercial printer? The only reason to impose is if you are printing it yourself, and for that you would probably want to use Print Booklet. Your online PDF should be single pages, in consecutive order, to make it easier for your readers.

The hard copy goes to a commercial printer. I also produce a low res PDF version which goes on the village web site (as per link above). The reasons I produce the PDF in the same fomat as the version that the commercial printer would get are a) in Corel it is easier than producing two separate versions and b) most people who are interested in the on-line version (ex-villagers) like to print their own hard copy. I gather that with InDesign I can produce in consecutive order and then decide whether to output in conscutive order or impose (? I am not certain about the meaning of the term "impose" in this context - does it mean produce a version with the double pages correctly numbered for the folded and stapled version? i.e. 1 & 8, 2 &7.

"Impose means to arrange pages in the proper order for printing and binding (known as printer's spreads). That's the printer's job, and you should not be doing it.

IN ID you should ALWAYS do the layout in consecutive order (1,2,3... known as reader's spreads) so you see what the reader will see. It makes it much easier to jusdge the design and to work with crossovers, if you have any.

Since this is going out for print you have no reason to impose, and you can export a hi-res version for the printer, then a low-res version for the web, all from the same .indd file.